Of what use can 140 characters be to a very large private bank in India? If those characters make a “tweet”, you will be surprised with the results. With the help of Mahesh Murthy, founder and CEO of search engine marketing firm Pinstorm, and his team, this private bank monitors around 1,600 tweets or conversations a day.

Murthy and his team respond to 200 to 300 tweets daily to either thank the twitter for a complimentary remark concerning the bank or “correct a perception” as Murthy puts it.

“Even simple things like not having enough cash in an ATM get reported in tweets. It is extremely important to react at the earliest to such problems and the tweets give the bank ample opportunity to take quick action, remedy the situation, and preserve their brand image in the bargain,” explains Murthy. The other tweets are ignored but nevertheless stored for future reference by the bank.

The bank is just a case in point. Since its creation in 2006 by Jack Dorsey, Twitter has gained extensive popularity. India, in fact, has an estimated 1.4 million twitters (Facebook would have around 8 million users while Orkut around 16 million users) and is the third-largest “tweeting” country after Germany and the US. It first came into the limelight during the 2008 Mumbai attacks, when eyewitnesses sent an estimated 80 tweets every five seconds. Twitter users on the ground helped compile a list of the dead and injured.

But globally too, Twitter is gaining from strength to strength. In just under three years the “tweet”, or humble SMS of the internet as it’s known, has crossed the five-billion mark globally. It’s a free social networking and micro-blogging service that asks a simple question “What are you doing?” The answers (or tweets) are displayed on the user’s profile page and delivered to other users (via mobiles too) who have subscribed to them (known as followers).

Over the last three years, tweets have been helping users in unimaginable ways. Twitter was famously used by candidates in the 2008 US presidential campaign. In Britain, the Department for Business, Innovation and Skills released a Twitter strategy written for the use of other departments.

This April, public health departments used Twitter to provide updates on H1N1 (swine flu) cases. And in May 2009, astronaut Mike Massimino used Twitter to send updates of the Hubble Space Telescope repair mission, the first time Twitter was used in space.

Even Hillary Clinton’s recent visit to India was covered on sites such as Twitter, Flickr and Facebook. The Americagov Twitter feed ( http://twitter.com/americagov ) was following the secretary every step of the way during her visits to Mumbai and New Delhi.

Tweets have been helping businesses too. IT majors like Tata Consultancy Services (TCS) and Infosys Technologies are on twitter. And so are politicians like the Minister of State for External Affairs Shashi Tharoor who courted controversy over his “cattle class” remarks on Twitter but still has nearly 3,50,000 followers (the highest in India). Movie stars like Priyanka Chopra and authors like Chetan Bhagat are also on twitter.

Twitter does not release the number of active users but it’s estimated that there are over 50 million global twitters currently. In comparison, Facebook has over 300 million users but has been around for over six years.

Twitter’s success, according to Avignyata social media catalyst Moksh Juneja, lies in the fact that “it can be accessed via the internet (GPRS connectivity), on mobiles and through applications (like tweetdeck) on the iPhone and Blackberry”.

And the tweets will only increase in India with India’s largest mobile operator, Bharti Airtel, partnering with Twitter and allowing the 100 million-odd Airtel subscribers to tweet without having to pay for an international SMS. Incoming updates are free. All they have to do is text “START” to 53000. Back in 2008, Twitter was available in India through SMS but the service was discontinued due to high costs.

But it has not been a smooth ride for Twitter. For instance, in October 2008, a draft US Army intelligence report identified Twitter as a “potential terrorist tool”. And now movie studios are beginning to put an anti-Twitter clause in stars’ contracts. Disney reportedly has a clause forbidding confidentiality breaches by way of social networks such as Twitter and Facebook or personal blog.

Critics have also called it “pointless babble” but Murthy counters: “It’s as useful or useless as a conversation can get. In fact, it’s the pulse of the people which you can choose to acknowledge or ignore.”